When you install the latest update, you'll also get all the previous updates if your Surface doesn't have them already. Only updates that apply to Surface will be downloaded and installed.

If you update the operating system on your Surface, your update history will be cleared.

Firmware updates can’t be uninstalled or reverted to an earlier version.

Updates are released in stages – not every Surface will receive the update at the same time, but it’ll be delivered to all devices. If you haven’t received an update, select the Start button, then select Settings > Update & security > Windows Update.